#173:The 14-15 Puzzle

Sam Loyd (1841-1911) was born in Philadelphia and lived in New York. Loyd was one of the greatest puzzle designers of his time and the 14-15 puzzle was perhpas his most infamous. This puzzle was a traditional sliding tile puzzle, arranged just like the one below. The challenge was to move the 14 and 15 tiles back to their correct position.

Loyd offered a $1000 prize for the first correct solution, an enormous amount of money back then, but it was never claimed, despite the thousands who say they performed the feat. He recounts that 'people became infatuated with the puzzle and ludicrous tales are told of shopkeepers who neglected to open their stores; of a distinguished clergyman who stood under a street lamp all through a wintry night trying to recall the way he had performed the feat. The mysterious feature of the puzzle is that none seem to be able to remember the sequence of moves whereby they feel sure they succeeded in solving the puzzle.'

Instead of tormenting you with his original 14-15 puzzle, here is a slightly easier version. What is the shortest way to move the tiles in order to get the vacant square from the bottom right to the top left corner and swap the 14 and 15 tiles?
At the end, all the tiles must be in numerical order, as follows (with the asterisk representing the blank square):